Senior Design Project Andres Rosa Anthony Lombardi David
Senior Design Project Andres Rosa Anthony Lombardi David Frazier Summer 2017 - EET 4950 P. H. A. B. S.
Presentation Overview • • • Purpose/ Goal Flowchart Concepts Behind measurements Hardware Utilized Testing Components and Results i. OS Application Coding Arduino Coding Budget Ethical, social, enrivonmental, etc. aspects Build Issues Future Improvements References
The What Proximity Sensing Heart Rate Monitoring Alerting Bracelet System P. H. A. B. S.
• Alzheimer’s Sufferers • Senior Citizens The Why • Hospitals • Military • Sports Teams
The Goal To design and build a bracelet which can monitor and alert based on a wearer’s condition and location.
Heart Rate - Radial Artery measurement
Hardware Adafruit Feather M 0 Bluefruit LE ● ● ● ● 32 -bit ARM Cortex M 0+ 48 Pins Runs on 3. 3 V 10 x Analog Pins 2. 0” x 0. 9” x 0. 28” dimension Low power consumption Bluetooth Built-in
Bluetooth n. RF 51 ● System on a Chip (So. C) Design ● 2. 4 GHz RF Tranceivers ● Very-low power consumption ● On-board antenna, off-board capable
Heart Adafruit 1093 Pulse Sensor ● ● ● APDS-9008 Light Photo Sensor 535 nm. 625” diameter ~4 m. A consumption Analog signal Photoplethysmogram
Global Positioning Adafruit Ultimate GPS Featherwing ● ● ● ● -165 d. Bm sensitivity 22 satellites on 66 channels 10 location updates per second 20 m. A current draw RTC with cell battery backup Built-In Datalogging Internal & external antenna options
Li-Ion/Li. Po Battery ● 500 m. Ah ● Small form factor ● Common-place in many technologies/devices
Li-Ion/Li. Po Charger ● MCP 73833 IC ● Charge/Load output capabilities ● USB Mini-B will charge the battery ● Current from 100 m. A to 1000 m. A
3 D Printing ● Plastics ● Many material types
Pulse Testing ● PPG (Photoplethysmograph) ● Measures flexing of skin due to pulse
GPS Testing ● NMEA Data (National Marine Electronics Association) ● “Sentences” which dileniate information ● Location, speed, altitude, satellite count, etc
GPS Testing ● ● Accuracy improves over connection period Measured within 6 ft
Application (i. OS) • Xcode, Swift • Similar to Objective-C • Less code required
3 D Printing • Evolution • ABS vs PLA plastic
3 D PRINTING
The Bluetooth Code • Setting up our Libraries and Switching our device to DATA Mode. • BLE – Bluetooth Low Energy • Send our output via the ble. print command. • Note our output is sent every 2 s via the if line statement.
The Heart Rate Code • Reading in from our input pin • Saving our time in microseconds • Calculating time interval • Shifting an array of time intervals to the right by 1. • Saving the new time interval into the array • Calculating BPM
Cost Analysis
Future Cost Analysis
Environmental Aspects • Battery re-chargeability • Plastics recyclability • Copper and other metals from boards/electronics
Health and Safety • Battery Location/Charging/Heat • Moisture
Ethical Aspects • Documentation of References • Information withheld from wearer • Designed to protect and look after loved ones
Social Aspects • Taking care of family is a “norm” • Time is finite • Altruism
Sustainability • • Recyclability Photoplethysmography widely used Technology improvements GPS is Government run
Build Issues • Board Failures • Printing • Tuning the BPM algorithm with interference issues and limited testing tools • Bluetooth distance
Board Failures • Our first Bluefruit LE microcontroller broke down spontaneously 4 weeks into building. After 1 week of troubleshooting, we purchased a replacement. • Bluetooth range for the replacement was much lower than the original
Printing • Machines • Calibration
Tuning the Parameters of BPM With Interference Issues and Limited Testing Tools • Bluetooth range for the replacement was much lower than the original. • Arduino IDE platform does not allow step through code so working on perfecting the values for our heart rate calculation was difficult. • Compounded with a noisy signal from the motion artifacts made finding the right balance nearly impossible.
Solution to the Noise Issue • Digital Filtering with the assistance of accelerometer readings as a secondary input. • This input would drive a correction that would compensate for the motion artifact noise. • Kalman, Least Mean Squared, ect…
Build Improvements • GSM/CDMA • Waterproofing/resistance • Custom PCB, smaller form factor • Accelerometer • Material change
Positive Outcomes • • Design and build “from scratch” Learned 3 D modeling Learned coding for an application Learned outside the scope of our coursework
References [1] En. wikipedia. org. (2017). Pulse. [online] Available at: https: //en. wikipedia. org/wiki/Pulse [2] Web. MD. (2017). Pulse Measurement. [online] Available at: http: //www. webmd. com/heart-disease/pulse-measurement#1 [3] Math of ECGs: Fourier Series [online]. Available: http: //www. intmath. com/blog/mathematics/math-of-ecgs-fourier-series-4281 [4] Pulse Wave Analysis [online]. Available: https: //www. intechopen. com/books/advanced-biomedical-engineering/pulse-wave-analysis [5] Tamura, T. ; Maeda, Y. ; Sekine, M. ; Yoshida, M. Wearable Photoplethysmographic Sensors—Past and Present. Electronics 2014, 3, 282 -302. [online, Journal]. Available: http: //www. mdpi. com/2079 -9292/3/2/282 [6] Bluetooth. com. (2017). How it works | Bluetooth Technology Website. [online] Available at: https: //www. bluetooth. com/what-is-bluetoothtechnology/how-it-works [7] Bluetooth LE Technology [online]. Available: https: //www. bluetooth. com/specifications/gatt/generic-attributes-overview [8] What Is GPS - Mechanical Engineering Blog, (2017). [online] Available at: http: //www. mechanicalengineeringblog. com/913 -what-is-gps/ [9] De. Priest, D. (2017). NMEA data. [online] Gpsinformation. org. Available at: http: //www. gpsinformation. org/dale/nmea. htm [10] The Scientist and Engineer's Guide to Digital Signal Processing. (2017). [ebook] p. 227. Available at: http: //www. analog. com/media/en/technicaldocumentation/dsp-book/dsp_book_Ch 15. pdf
References Continued [11] Research Gate. (2017). Wearable Photoplethysmographic Sensors - Past and Present. [online] Available at: https: //www. researchgate. net/figure/261913909_fig 5_Figure-5 -Block-diagram-of-an-adaptive-filter-with-an-accelerometer [12] En. wikipedia. org. (2017). Least mean squares filter. [online] Available at: https: //en. wikipedia. org/wiki/Least_mean_squares_filter [13] Industries, A. (2017). Adafruit Feather M 0 Bluefruit LE ID: 2995 - $29. 95 : Adafruit Industries, Unique & fun DIY electronics and kits. [online] Adafruit. com. Available at: https: //www. adafruit. com/product/2995 [14] Atmel SAM D 21 E / SAM D 21 G / SAM D 21 J. (2017). [ebook, datasheet] Available at: https: //cdn-shop. adafruit. com/product-files/2772/atmel 42181 -sam-d 21_datasheet. pdf [15] Nordicsemi. com. (2017). n. RF 51822 / Bluetooth low energy / Products / Home - Ultra Low Power Wireless Solutions from NORDIC SEMICONDUCTOR. [online] Available at: https: //www. nordicsemi. com/eng/Products/Bluetooth-low-energy/n. RF 51822 [16] Industries, A. (2017). Pulse Sensor Amped ID: 1093 - $25. 00 : Adafruit Industries, Unique & fun DIY electronics and kits. [online] Adafruit. com. Available at: https: //www. adafruit. com/product/1093 [17] World Famous Electronics llc. (2017). Open Hardware. [online] Available at: https: //pulsesensor. com/pages/open-hardware [18] Cdn. shopify. com. (2017). Pulse Sensor Schematic. [online] Available at: https: //cdn. shopify. com/s/files/1/0100/6632/files/Pulse. Sensor. Ampd__Schematic. pdf? 1862089645030619491
References Continued [19] APDS-9008, Miniature Surface-Mount Ambient Light Photo Sensor. (2017). [ebook, datasheet] Available at: https: //docs. broadcom. com/docs/AV 02 -1169 EN [20] Kingbright - Subminiature Solid State Lamp. (2017). [ebook, datasheet] Available at: http: //www. kingbrightusa. com/images/catalog/SPEC/am 2520 zgc 09. pdf [21] Learn. adafruit. com. (2017). Overview | Adafruit Ultimate GPS featherwing | Adafruit Learning System. [online] Available at: https: //learn. adafruit. com/adafruit-ultimate-gps-featherwing/overview [22] Adafruit Ultimate GPS Featherwing. (2017). [ebook, datasheet] “Lady Ada”. Available at: https: //cdn-learn. adafruit. com/downloads/pdf/adafruitultimate-gps-featherwing. pdf [23] Industries, A. (2017). Lithium Ion Polymer Battery - 3. 7 v 500 m. Ah ID: 1578 - $7. 95 : Adafruit Industries, Unique & fun DIY electronics and kits. [online] Adafruit. com. Available at: https: //www. adafruit. com/products/1578 [24] Industries, A. (2017). USB Li. Ion/Li. Poly charger [v 1. 2] ID: 259 - $12. 50 : Adafruit Industries, Unique & fun DIY electronics and kits. [online] Adafruit. com. Available at: https: //www. adafruit. com/products/259 [25] Microchip. com. (2017). MCP 73833 - Battery Management and Fuel Gauges - Battery Chargers. [online] Available at: http: //www. microchip. com/wwwproducts/en/en 027785
Questions, Comments, Concerns Thank you for your time. Special Thanks to Professors Notash and Ejaz for their guidance and support throughout. Group Webpage (As needed)
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